With the development of multimedia technology, categories of multimedia devices enabling people to enjoy multimedia audio-visual functions are changing with each passing day. The present invention relates to a multimedia device that possesses a camera and a loudspeaker array and needs to achieve surround sound effect. For the sake of convenience, smart television is taken as an example to elaborate the invention here.
With the improvement of television manufacturing technology and display technology, household televisions become lighter and thinner and pictures are clearer and brighter. Correspondently, people have a higher requirement for audio player system.
Currently, smart television has possessed a light thin player system, for example, Soundbar, substituting the loudspeaker array for 5.1 player system which is of large volume and scattered arrangement. The loudspeaker array has a built-in digital signal processing chip which can accomplish sound processing. But one defect of the light thin loudspeaker array is insufficient surround sound effect. Existing solutions are Dipole stereo extension technology and beamforming technology, etc. Dipole has a relatively small listening area and has restriction for sitting position of users, thus it is difficult to create abundant surround sound in a larger area. And the beamforming technology can make full use of inner structure of the hall and array characteristics, so that the sound from the loudspeaker array can form a sound beam pointing to wall, thus abundant surround sound effect can be created in the entire hall using multiple reflections and scatterings by the wall.
However, prior technology that uses beamforming to create surround sound in the hall must have an acoustic calibration process in order to ensure that the sound beam indeed points to side wall and produces the reflection and surround effect. Therefore, the following problems are caused: First, manual calibration is needed before the loudspeaker array is used, thus the process is tedious. Second, additional calibration device is needed, such as measurement microphone, etc. Third, the listening position of users is limited to a narrower scope. If the users want to enjoy a favorable surround sound effect in other positions, the loudspeaker array needs to be calibrated again.